Latch unit for sliding-type doors

ABSTRACT

A latch unit, to secure a sliding-type door to the door frame, comprising a rotatably mounted hook on a stile of the door and adapted by inside finger-lever manipulation for movement between a retracted unlatched position and an advanced latched position projecting in downwardly opening relation through a vertical slot in the adjacent doorframe jamb and engaging over the lip at the lower end of such slot; the hook being an integral part of a finger-lever operated rotary plate, such plate being camlike and having a pair of edges of predetermined position and configuration, and a leaf spring peripherally engaging the rotary plate, said spring yieldably bearing on one such edge to maintain the hook in retracted position and yieldably bearing on the other edge to maintain the hook in advanced position while springurging said hook downwardly against said lip to prevent escape therefrom upon the door being vertically jounced from the outside.

limited States Patent [72] Inventor Jack H. Jensen Danville, Calif.

21 1 Appl. No. 44,424

[22] Filed June 8, 1970 [45] Patented Dec. 7, 1971 [73] Assignee RylockCompany, Ltd.

Union City, Calif.-

[54] LATCH UNIT FOR SLIDING-TYPE DOORS 1 Claim, 4 Drawing Figs.

[52] U.S. Cl 292/128, 70/D1G. 52, 292/228 [51] Int. Cl E05c 19/12 [50]Field 01 Search 292/56.

3,174,783 3/1965 Russell 292 103 .2,742,3o9 4/1956 Hillgren 292/101xFOREIGN PATENTS 9,865 1395 GreatBritainW; 292/128 PrimaryExaminer-Robert L. Wolfe AnomeyWebster and Webster ABSTRACT: A latchunit, to secure a sliding-type door to the door frame, comprising arotatably mounted hook on a stile of the door and adapted by insidefinger-lever manipulation for movement between a retracted unlatchedposition and an advanced latched position projecting in downwardlyopening relation through a vertical slot in the adjacent doorframe jamband engaging over the lip at the lower end of such slot; the hook beingan integral part of a finger-lever operated rotary plate, such platebeing camlike and having a pair of edges of predetermined position andconfiguration. and a leaf spring peripherally engaging the rotary plate,said spring yieldably bearing on one such edge to maintain the hook inretracted position and yieldably bearing on the other edge to maintainthe hook in advanced position while spring-urging said hook downwardlyagainst said lip to prevent escape therefrom upon the door beingvertically jounced from the outside.

LATCH UNIT FOR SLIDING-TYPE DOORS BACKGROUND OF THE INVENTION Inconventional sliding-type doors (such as those of glass in a metallicframe) there is commonly a certain amount of vertical loose playpossible between the door and its frame, and which loose play permitsthe door to be vertically jounced to cause the downwardly openinghook-of the latch unit on a stile of the door-to escape from engagementwith the hookreceiving lip on the adjacent jamb of the door frame. Inthis way, it has heretofore been possible for unauthorized persons tounlatch and open the door and thus gain access to the house or otherstructure provided with such door. The present invention was developedin the course of seeking a solution to such problem.

SUMMARY OF THE INVENTION The present invention provides, as a majorobject, a latch unit, for a sliding-type door, which is tamper-proof inthe sense that such latch unit cannot be released or unlatched fromoutside the door by vertically jouncing the latter.

The present invention provides, as another important object, a latchunit as above-on a stile of the door and adapted to secure the same tothe door framewhich includes a rotatably mounted hook adapted by insidefinger manipulation for movement between a retracted unlatched positionand an advanced latched position projecting in downwardly openingrelation from said stile of the door, through a vertical slot in theadjacent doorframe jamb, and engaging over the lip at the lower end ofsuch slot; there being novel means associated with the hook operative,in said advanced latched position thereof, to maintain the hook againstescape from said lip upon vertical jouncing being imparted to the doorfrom outside thereof.

The present invention provides, as still another important object, alatch unit-as above-wherein said novel means comprises a rotary plate ofwhich the hook is an integral part, such plate being camlike and havinga pair of edges of predetermined position and configuration, and a leafspring yieldably bearing on one such edge to maintain the hook in saidretracted position and yieldably bearing on the other edge to maintainthe hook in said advanced position.

The present invention provides, as a further object, a latch unit whichis designed for ease and economy of manufacture, and ready installation.

The present invention provides, as a still further object, a practical,reliable, and durable latch unit, and one which is exceedingly effectivefor the purpose for which it is designed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation showing thelatch unit mounted on a stile of a sliding-type door; the unit beingshown as latched.

FIG. 2 is an enlarged elevation of the latch unit; the view lookingforward from the back of such latch unit, and the latter being shown asunlatched.

FIG. 3 is a view similar to FIG. 2 but shows the latch unit as latched.

FIG. '4 is a plan view, partly in section, taken directly below thelower end of the leaf spring.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularlyto the drawings and to the characters of reference marked thereon, thelatch unit, indicated generally at l, is mounted on the outer stile 2 ofa sliding-type door 3; such door being carried in a frame 4 whichincludes a jamb 5 against which the stile 2 makes contact when the dooris closed.

When the door is latched closed, a downwardly opening hook 6 projectsfrom the latch unit 1 through a vertical slot 7 in the face 8 of jamb 5;the hook engaging over the lip 9 at the lower end of said slot 7 asshown in FIG. 3.

The latch unit 1 includes a support or housing I0, in the form of aninwardly facing channel, secured to the stile 2 by bolts 11; there beinga handgrip 12 conventionally attached in standoff relation to thehousing 10.

A transverse stub shaft 13 is journaled on the housing 10, andexteriorly thereof is fitted with a finger lever 14, while inside saidhousing the shaft 13 is provided-by means of a hub l5--with a rotaryplate I6 of which the hook 6 is an integral part.

When the finger lever 14 is projecting upward, as in FIG. 3, such rotaryplate is disposed in a rotative position with said hook 6 projectingoutwardly through a cutaway 17 in housing 10, and thence through thevertical slot 7 in the face 8 of jamb 5, with the hook engaged over thelip 9. This is the advanced latched position of the hook 6.

When the finger lever I4 is projecting downward, as in FIG. 2, therotary plate 16 is disposed in a rotative position with the hook 6retracted into the housing and bearing against the inner side of thelatter as a stop. This is the retracted unlatched position of the hook6.

The rotary plate 16 is formed-at its periphery, and in endto-endrelation-with a straight edge 18 and a curved edge 19; the straight edge18 being disposed substantially perpendicular rearwardly of andprojecting, in rearwardly facing relation, above the shaft 13 when thehook 6 is in its advanced latched position. The curved edge 19 isdisposed rearwardly of the shaft 13 and has an upwardly facing portionwhen the hook 6 is in its retracted unlatched position.

A generally upright leaf spring 20 is disposed in the housing 10 betweenthe rotary plate 16 and a plug 21 in the top of such housing; such plugfixedly anchoring the upper end of said leaf spring 20 to the housing atthe outer side thereof.

At its lower end, the leaf spring 20 bears-relatively forcefully butyieldably-on the periphery of the rotary plate.

More particularly, the leaf spring 20 engages-when the hook 6 is in itsadvanced latched position as in FIG. 3-with an outward thrust againstthe then-upstanding straight edge 18 at a point above the shaft 13whereby the rotary plate is urged in a rotative direction to hold thehook in engagement over the lip 9 at the lower end of the slot 7 in theface 8 of jamb 5. Consequently, if a person-seeking unauthorizedentry-vertically jounces the door 3 (and which is commonly possible dueto loose play between the door and its frame), the hook 6 remainsengaged over and with the lip 9, merely rising and falling with such lipas the door is so jounced; it not being possible for the hook to bouncefree.

When the hook 6 is in its retracted unlatched position as in FIG. 2, theleaf spring 20 engages, with a downward thrust, against the upwardlyfacing portion of the curved edge 19 at a point rearwardly of the shaft13 whereby the rotary plate is urged in a rotative direction to hold thehook 6 against the inner side of housing I0 as a stop.

While the leaf spring 20 is effective to hold the rotary plate 16, andits hook 6, in either of its working positions, such spring does yieldin response to motion imparted to said rotary plate and hook uponmanipulation of finger lever 14 from in- 4 side the door to latch orunlatch the same.

From the foregoing description, it will be readily seen that there hasbeen produced such a latch unit as substantially fulfills the objects ofthe invention, as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the latch unit, still in practice such deviations fromsuch detail may be resorted to as do not form a departure from thespirit of the invention as defined by the appended claims.

I claim:

1. A latch unit, to secure a sliding-type door to its frame, comprisingan upright channel facing and secured on the door stile which isadjacent a jamb of the frame when the door is closed, a hook, the hookbeing an integral part of a transverse axis rotary plate journaled inconnection with the channel and disposed therein, a finger leverexteriorly of the channel adapted to rotate the plate to move the hookbetween a retracted unlatched position wholly within the channel and anadvanced latched position projecting in downwardly opening relation fromthe channel through a slot in the outer side thereof and a correspondingslot in said jamb, the hook in said advanced latched position engagingover a lip in the lower end of said corresponding slot, a plug in theupper end of the channel, and a leaf spring anchored at its upper end inthe channel at the outer side thereof by the plug and thence dependingat a downward and rearward incline in the channel to engagement underload and at its lower end against the periphery of the rotary plate,said rotary plate having two endmerged peripheral edges, ofpredetermined position and configuration, with which said springengages, selectively; said leaf spring yieldably bearing on one suchedge to maintain the hook in retracted unlatched position, and yieldablybearing on the other edge to maintain the hook in advanced latchedposition;

said one edge being disposed rearwardly of the axis of the rotary platewhen the hook is in retracted unlatched position and then having anupwardly facing portion against which the spring yieldably bears with adownward thrust whereby to urge the rotary plate in a direction suchthat said plate is placed under load and caused to rest against theinner side of the channel as a stop; and said other edge being disposedrearwardly of and projecting, in rearwardly facing relation, upwardlyrelative to the axis of the rotary plate when the hook is in advancedposition, the spring then yieldably bearing with an outward thrust onsaid other edge at a point above such axis whereby said spring urges therotary plate in a direction such that the hook is placed under load andcaused to remain in engagement with said lip and prevented from escapethereof should the door be vertically jounced relative to the frame.

* I I I. k

1. A latch unit, to secure a sliding-type door to its frame, comprisingan upright channel facing and secured on the door stile which isadjacent a jamb of the frame when the door is closed, a hook, the hookbeing an integral part of a transverse axis rotary plate journaled inconnection with the channel and disposed therein, a finger leverexteriorly of the channel adapted to rotate the plate to move the hookbetween a retracted unlatched position wholly within the channel and anadvanced latched position projecting in downwardly opening relation fromthe channel through a slot in the outer side thereof and a correspondingslot in said jamb, the hook in said advanced latched position engagingover a lip in the lower end of said corresponding slot, a plug in theupper end of the channel, and a leaf spring anchored at its upper end inthe channel at the outer side thereof by the plug and thence dependingat a downward and rearward incline in the channel to engagement underload and at its lower end against the periphery of the rotary plate,said rotary plate having two end-merged peripheral edges, ofpredetermined position and configuration, with which said springengages, selectively; said leaf spring yieldably bearing on one suchedge to maintain the hook in retracted unlatched position, and yieldablybearing on the other edge to maintain the hook in advanced latchedposition; said one edge being disposed rearwardly of the axis of therotary plate when the hook is in retracted unlatched position and thenhaving an upwardly facing portion against which the spring yieldablybears with a downward thrust whereby to urge the rotary plate in adirection such that said plate is placed under load and caused to restagainst the inner side of the channel as a stop; and said other edgebeing disposed rearwardly of and projecting, in rearwardly facingrelation, upwardly relative to the axis of the rotary plate when thehook is in advanced position, the spring then yieldably bearing with anoutward thrust on said other edge at a point above such axis wherebysaid spring urges the rotary plate in a direction such that the hook isplaced under load and caused to remain in engagement with said lip andprevented from escape thereof should the door be vertically jouncedrelative to the frame.